str1 = 'aa'
str2 = 'bb'

list1 = [1, 2]
list2 = [10, 20]

t1 = (1, 2)
t2 = (10, 20)

dict1 = {'name': 'Tom'}
dict2 = {'age': 20}

# + ：合并，支持 字符串、列表、元组
print(str1 + str2) # aabb
print(list1 + list2) # [1, 2, 10, 20]
print(t1 + t2) # (1, 2, 10, 20)
# print(dict1 + dict2) # !!! 报错